fix bogus path_put() of nd->root after some unlazy_walk() failures

Failure to grab reference to parent dentry should go through the
same cleanup as nd->seq mismatch.  As it is, we might end up with
caller thinking it needs to path_put() nd->root, with obvious
nasty results once we'd hit that bug enough times to drive the
refcount of root dentry all the way to zero...

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

diff --git a/fs/namei.c b/fs/namei.c
index 8f77a8c..c53d3a9 100644 (file)
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -513,8 +513,7 @@ static int unlazy_walk(struct nameidata *nd, struct dentry *dentry)
 
        if (!lockref_get_not_dead(&parent->d_lockref)) {
                nd->path.dentry = NULL; 
-               rcu_read_unlock();
-               return -ECHILD;
+               goto out;
        }
 
        /*